> https://morph.zone/modules/newbb_plus/viewtopic.php?topic_id=12785&forum=53&start=7
> [...] 5450

While comment #9 in that linked thread says that HD 5450 works, comments #17 and #26 in this very thread say it doesn't. So compatibility seems to depend on the specific card, not just the Radeon GPU, as has been outlined there.

> 5870

HD 5870 is not mentioned in the linked thread.